The invention concerns an apparatus and technique for protecting sensitive electronic components against the high accelerations encountered in a tank-fired projectile, for instance.
In most applications involving electronics in high launch force environments, the components are mounted on circuit boards, the interconnects between boards and components are made, and the entire module is solid potted with a suitable resin. This method has at least two notable shortcomings. In the event of a component failure, or if for any reason it is required to replace a component internal to the potted module, access to the component may require an arduous effort to remove the potting, a process which often damages other components and compromises the integrity of the total structure. Additionally, the standard method does not provide for special shock isolation of especially fragile components. The technique described eliminates both of these deficiencies and also enables the attenuation of selected frequency regions resulting from the applied accelerations.
Hardening of components and assemblies is based on the response shock spectrum to obtain the required frequency for proper design of the shock isolation system. In order to specify the optimum isolation for a particular assembly, it is necessary to determine the mass properties of the assembly along with those of the shock isolation system. In ,order to specify the optimum isolation for a particular assembly, it is necessary to determine the mass properties of the assembly along with those of the critical components comprising it. This information relates to the susceptibility of a given component to failure by shock loading as a function of the frequency content of the applied load. By analyzing the frequency content of the applied load, it is possible to construct a convenient analytical representation of the shock pulse that will produce this spectrum of response. In this form, the load spectrum can be analytically applied to the assembly to determine the response of that assembly. To minimize the risk of damage to the assembly, it is required to attenuate frequency regions in the applied load that correspond to critical frequency regions in the specimen.
It is the purpose of the present invention to eliminate the correspondence of such spectra and to demonstrate a methodology involving selected non-linear elastomer springs which produce the desired isolation.